Linux Shell script (bash) to change IP address of remote machine using SSH - linux

Question

I'd like to have a shell script to change the IP address of a remote machine using SSH.
The problem I am having is that both SSH and remote commands require passwords. I am using 'expect' to handle the password input and this works works well in isolation for each step, but not combined.
i.e. I have a separate script on the remote machine to change the IP address. This works when running manually on the remote machine.
#!/usr/bin/expect -f
set ipaddr [lindex $argv 0]
set password "mypassword"
set timeout 2
if {[llength $argv] == 0} {
send_user "Usage: ./set_ip.sh ipaddress/24\n"
exit 1
}
spawn sudo nmcli dev modify eth0 ipv4.addresses $ipaddr
expect {
password { send "$password\r" ; exp_continue }
timeout { send_user "\nFailed to get password prompt\n"; exit 1 }
eof exit
}
close
And I have a script to perform the SSH, then call the above remote script
#!/usr/bin/expect -f
set target [lindex $argv 0]
set newipaddr [lindex $argv 1]
set password "mysshpassword"
set timeout 2
spawn ssh $target
expect {
password: {send "$password\r"}
timeout { send_user "\nFailed to get password prompt\n"; exit 1 }
eof exit
}
send "~/set_ip.sh $newipaddr/r"
send "exit\r"
close
When the remote script gets called, it seems to run okay but the password prompt following the nmcli command is never received.
If someone could advise where I am going wrong I'd be grateful.
Also, this is the first time I've used bash, so feel free to express critique.
Thanks